1. Field of the Invention
The invention relates generally to the field of well log data acquisition and interpretation. More specifically, the invention relates to methods and systems for display of well log data and information ancillary to such well log data as used in interpretation thereof.
2. Background Art
Well logs are measurements, typically with respect to depth, of selected physical parameters of earth formations penetrated by a wellbore. Well logs are typically recorded by inserting various types of measurement instruments into a wellbore, moving the instruments along the wellbore, and recording the measurements made by the instruments. One type of well log recording includes lowering the instruments at the end of an armored electrical cable, and recording the measurements made with respect to the length of the cable extended into the wellbore. Depth within the wellbore is inferred from the extended length of the cable. Recordings made in this way are substantially directly correlated to measurement depth within the wellbore. Another method for measurement is known as xe2x80x9clogging while drillingxe2x80x9d (LWD) and includes attaching the instruments to the lower portion of a drilling tool assembly used to drill the wellbore. Some of the measurements are made by transmitting them to the surface using a pressure modulation telemetry system, which modulates pressure of a drilling fluid (mud) flowing through the interior of the drilling tool assembly. A much larger amount of well log data is stored in a recording device disposed in the logging instrument, which is interrogated when the instrument is retrieved from the wellbore. This information is typically recorded with respect to time. A record of instrument position in the wellbore with respect to time made at the earth""s surface is then correlated to the time/measurement record retrieved from the instrument storage device to generate a conventional xe2x80x9cwell logxe2x80x9d of measurements with respect to wellbore depth.
Well logs are typically presented in a graphic form including a plurality of grids or xe2x80x9ctracksxe2x80x9d each of which is scaled from a selected lower value to a selected upper value for each measurement type presented in the particular track. A xe2x80x9cdepth trackxe2x80x9d or scale which indicates depth in the wellbore, is typically positioned between two of the tracks. Depending on the needs of the particular user, any number of or type of measurements may be presented in one or more of the tracks. A typical well log presentation of an individual measurement is in the form of a substantially continuous curve or trace. Curves are interpolated from discrete measurement values stored with respect to time and/or depth in a computer or computer-readable storage medium. Other presentations include gray scale or color scale interpolations of selected measurement types to produce the equivalent of a visual image of the wellbore wall. Such xe2x80x9cimagexe2x80x9d presentations have proven useful in certain types of geologic analysis.
Interpreting well log data includes correlation or other use of a very large amount of ancillary information. Such information comprises the geographic location of the wellbore (e.g. global positioning satellite data), and geologic and well log information from adjacent wellbores. Other information comprises the types of instruments used, their mechanical configuration and records relating to their calibration and maintenance. Still other types of information include the actual trajectory of the wellbore, which may traverse a substantial geographic distance in the horizontal plane with respect to the surface location of the wellbore. Other information of use in interpreting well log data includes data about the progress of the drilling of the wellbore, the type of drilling fluid used in the wellbore, environmental corrections applicable to the particular logging instruments used.
Methods known in the art for making the ancillary information available to a user of a well log includes transporting physical records to the wellbore, such as by magnetic diskette or paper copy, and including the transported records into the final record of the well log. Inclusion into the final well log may be made by manual entry of data such as by keyboard or other xe2x80x9cdownloadxe2x80x9d of the data into the recording system which makes the record of the measurements at the wellbore site (xe2x80x9cwellsitexe2x80x9d).
Much of this ancillary information is applicable to any well log recorded with a particular type of well logging instrument. For example, an instrument which measures naturally occurring gamma radiation (xe2x80x9cgamma rayxe2x80x9d) has environmental corrections which correspond only to the type of instrument. As one example, each wireline type gamma ray device of a selected external diameter from a particular wireline operator will have the same environmental corrections for xe2x80x9cmud weightxe2x80x9d (drilling fluid density). Other types of ancillary information are made available from the wellbore operator (typically an oil and gas producing entity). Examples of this type of information are the geographic location of the wellbore and any information from other wellbores in the vicinity. Still other types of ancillary information include records of initial and periodic calibration and maintenance of the particular instruments used in a particular wellbore.
The foregoing is only a small subset of the types of ancillary information which may be used in interpreting a particular well log. Irrespective of the type of ancillary information, transportation of this information, and its inclusion in each and every well log data record made at a particular wellsite can be expensive and cumbersome, particularly with respect to the needs for storage of such information. Particularly where a large number of wells are logged using similar or the same instruments, or in a geographic location having a large number of closely spaced wellbores, redundant storage of such ancillary information can be expensive and cumbersome.
It is known in the art to transmit well log data substantially in xe2x80x9creal timexe2x80x9d (at the time of acquisition) from a wellsite to a remote location (such as a user office). See for example, U.S. Pat. No. 6,101,445 issued to Alvarado et al. The system disclosed in the ""445 patent is adapted so that a user may view and use well log data as it is being recorded. To use the data in various applications, it is necessary to download or otherwise transfer the received data to the selected application.
U.S. Pat. No. 5,873,049 issued to Bielak et al. discloses a system for using data having a plurality of formats in determining an earth model using application programs adapted to read different types and/or formats of data. The system in the ""049 patent has no facility for use of data during acquisition at the wellsite.
U.S. Pat. No. 6,070,125 issued to Murphy et al. discloses a system for providing a geologic interpretation of various forms of data acquired from a wellbore, including well log data, seismic data, and drilling performance data. There is no facility in the system disclosed in the ""125 patent for remote access and display of wellbore data ancillary to data recorded at the wellsite.
U.S. Pat. No. 6,128,577 issued to Assa et al discloses a system for modeling and evaluating models of geologic structures from various wellbore data sources. A method disclosed in the ""577 patent includes organizing data into a database part and a design part. A shape of a geologic feature determined during feature classification is retained. A feature is divided into a first sub region and a second sub region having a boundary therebetween. A material property is assigned to each sub region. The sub region is divided into a plurality of sub regions, and the material property is propagated to the plurality of sub regions. The method and system disclosed in the ""577 patent provides no facility for using data stored at a remote location to view and process data presented and/or recorded at a different location.
U.S. Pat. No. 6,366,988 B1 issued to Skiba et al discloses a method and system for electronic data storage management. The system includes a means for moving data from a first storage location to a new storage destination, means for communicating the new destination to the first storage location, a means for translating the new destination to application programs, so that the application programs do no detect a change in location of the stored data, a means for updating the application programs so that they access data as if they were stored in the first location, and a means for transferring an operating system to the new destination so that the operating system can access the data at the new destination. There is no facility in the system disclosed in the ""988 patent for accessing and displaying data ancillary to data recorded at a wellsite.
U.S. Pat. No. 5,237,539 issued to Selman discloses a method and system for processing and displaying data recorded during drilling of a wellbore. The system disclosed in the ""539 patent is concerned with presenting data recorded in xe2x80x9creal timexe2x80x9d (such as rotary drill speed, axial force on a drill bit, and mud pump flow rates) with so-called xe2x80x9clagxe2x80x9d data, primarily samples of cuttings made during drilling of the wellbore, which are time delayed due to the amount of time between actual cutting of the rock and delivery of the drill cuttings to the earth""s surface from the wellbore. The system disclosed in the ""539 patent has no facility for accessing and/or displaying ancillary data to the data recorded at the wellsite.
U.S. Pat. No. 6,195,092 B1 issued to Dhond et al. discloses a software system for creating and editing multiple presentations of data in well log plots. The system includes presenting a spreadsheet-like data editor screen of a graphic user interface, displaying a plurality of well log data objects within the editor screen, displaying attributes of each of the objects in the editor, changing a value of one of the attributes, and automatically applying the changed attribute to the plurality of well log objects. To summarize the problem that is solved by the system in the ""092 patent, log presentation systems typically required changing presentation attributes for each display area on a well log, even if there were multiple presentations of the same data type on different parts of the well log. The system of the ""092 patent treats each log data parameter as an object. Changes to the attributes of one object propagate to all presentations of that same data object in any particular well log or well logs. There is, however, no facility in the system disclosed in the ""092 patent for accessing or using data that are ancillary to the data being processed by the system.
What is needed is a system for access to ancillary well log information which does not require physical transportation or manual data entry to a particular well log record in order to display and use these data.
One aspect of the invention is a method for viewing well log data is disclosed. The method includes, entering a wellbore identifier into a remote display device. The display device is at a first location separate from a facility controlled by a well logging operator. The well identifier is transmitted to a first database having ancillary data therein. The first database is controlled by the well logging operator. The ancillary data are sent to the first location, and the ancillary data and data recorded from a well logging instrument disposed in a wellbore are presented on the display device.
Another aspect of the invention is a method for viewing well log data. The method according to this aspect includes selecting a well identifier, accessing well log and ancillary data corresponding to the well identifier, generating and displaying a table of contents, and displaying data corresponding to ones of data types selected by a user from the table of contents.
Another aspect of the invention is a system for displaying well logging data. A system according to this aspect of the invention includes a display device operatively coupled to a first communications link. The display device is disposed at a first location. A first database is disposed at a second location. The first database is operatively coupled to the first communications link. The first database is adapted to return ancillary data corresponding to a selected wellbore upon transmission of an identifier from the display device to the first database. The system includes means for communicating well log data recorded at a wellsite to the display device. In one embodiment, a second communications link is operatively coupled between the display device and a well log recording unit at the wellsite.